Sound-producing device suitable for sirens or like instruments.



110. 736,428. PATBNTEDAUG. 1a, 1903. v r J. P. NORTHEYL, SOUND PRODUCING DEVICE SUITABLE FOR SIRENS 0R LIKE INSTRUMENTS.

APPLICATION IILED'NOV. 22. 1902.

H0 MODEL.

JOHN PELL NORTHEY,

Patented August18, 1903..

ATENT FFIGE.

OF TORONTO, CANADA.

SOUND-PRODUCING DEVICE SUITABLE FOR SIRENS OR LlKE INSTRUMENTS.

$PIECIFICATIO1 forming part of Letters Patent No. 736,428, dated August 18, 1903. Application filed November 22, 1802. Serial No. 132,428. (lilo model.)-

To all whom it may concern:

Be it known that I, JOHN PELL NORTHEY, manufacturer, of the city of Toronto, in the county of York, in the Province of Ontario, Canada, have invented'certainnew and useful Improvements in Sound-Producing Devices Suitable for Sirens or Like Instruments,

of which the following is a specification.

My invention relates to improvements in sound-producing devices suitable for sirens and like instruments; and the object of the invention is to improve the construction of the diaphone and produce a simple means for economically operating the same and yetproduce a uniform or even note of great carrying power; and 1t consists, essentially, of a casin g provided with a suitable cover, a compressedair or suitable low-pressure-fluid supplying pipe leading to the casing and to passageways in the internal cylinder thereof, a suitable resonator or trumpet screwed in the easing and forming a continuation of the cylinder, a piston situated within the cylinder and provided with passage-ways extending to the passage-ways in the cylinder aforesaid and having an enlarged head and passage-ways .leading through the edge thereof and located within an enlarged chamber, the main casing also being provided with orifices leading to the chamber surrounding the enlarged head of the piston, such orifices being supplied with air at a comparatively high pressure through a supplemental air-pipe, and passageways being made in the casing to lead behind the piston, and the parts being otherwise arranged and constructed in detail as hereinafter more particularly explained.

.The drawing represents a sectional view of my improved sound-producing device or signaling-siren.

A is the interior cylinder, which is provided with flanges a and passage-ways 0t.

B is the exterior casing, which is screwed onto the threaded circular exterior of the cylinder A.

. an entrance-pipe B, through which it is designed to introduce air at a comparatively low pressure-say at about 20 pounds.

The

casing B is also provided with a circumferential wall 19, which extends to the wall of the entrance-pipe B.

' p B is an entrance-pipe leading into the The-casing B. is providedwithchamber B formed between the walls I) and the exterior-Wall of the casing B.

. Ois anannular plate which is screwed into the interior of the casing B, so as to abut the flange a, of the cylinder A.

@D is theresonator, which is screwed into the threaded interior of the plate 0. E isan'annular plate which is screwedinto the threaded interior periphery of the casing B opposite to the flange a and so as to leave an annular passage-way a B represents passage ways extending through the wall I) of the casing l3 opposite the passage-waysa F is a ring which is of the same internal diameter as the inwardly-extending flange e of the ring E, such ring forming a passageway f between the flange e and the enlarged plate E. V

G is the cover-plate, which is fastened to the ring F by suitable cap-screws g, such plate G' forming, with the ring F, the remainder of the passage-ways f.

H is a pistonwhich isprovided with a series of orifices h, corresponding in number to the orifices a oflthe cylinder A. The orifices a, as Wellas the orifices h, are annular orifices.

The cylinder A is cast or formed with ribs A, which of course extend across the orifices a and between the flanges a, and thereby enable the casting to be made so as to leave the orifices. The ribs A are preferably exterior ribs. The piston H, however, is provided with interior ribs or wings H, by which I am enabled to cast the piston in one, so as to leave the enlarged orifices, as well as the orifices 72. in the enlarged piston-head H.

As hereinbefore stated, the air at low pressure-say at twenty poundsis introduced through the pipe B and through the openings orpassage-ways a in the cylinder A. The air at high pressure-say one hundred pounds-- is introduced through the pipe I) and the passage-ways b and a to the front of the enlarged head and forces such head backwardly until the air passes through the passage-wayf to the back of the head and forces the head forwardly again and exhausts through the pas sage-ways h In doing so the head, and consequently the piston, is continuously vibrated fice a, through which the air passes at low pressure, and thereby the requisite sound, tone?) or note is produced through the resonator By the construction I have adopted it will be understood that I produce the sound through low pressure and impart the required movement to the piston by comparatively smaller orifices at high pressure, thereby materially reducing the cost or expense in producing the sound, which is of course an important desideratum.

What I claim as my invention is- 1. In a sound-producing device, the combination with the cylinder having orifices and the piston having orifices corresponding to the same and asuitable head, of the pipe designed to discharge air at low pressure to and through the orifices in the cylinder and piston and the pipe designed to discharge air at high pressure against the head of the cylinder, so as to vibrate it as and for the purpose specified.

2. In a sound-producingdevice, the combination with the cylinder having passage-ways and the resonator leading therefrom, of the exterior casing forming a chamber around the cylinder, a low-pressure-air pipe leading directly to the cylinder through the casing, a high-pressure-air pipe leading to the exterior chamber, the piston having passage ways corresponding to the passage-ways in the cylinder and having an enlarged head fitting within the chamber in the casing, said casing and cylinder having passage-ways to carry the air under high pressure to the chamber surrounding the head, whereby such head is vibrated as and for the purpose specified.

'3. In a sound-producing device, the combination with the cylinder having orifices and flanges and the casing surrounding the same, and fitted onto the threaded exterior of the flanges of the cylinder and forming a chantber around such cylinder andthe pipe designed to discharge air at low pressure through the orifices of the cylinder and piston and the pipe designed to discharge air at high pressure into the chamber, of the piston having passage-ways corresponding to the passage-ways in the cylinder, an enlarged head provided with an annular opening, a ring surrounding the head and forming a passageway to the chamber in which the head is located in continuation of the passage-way extending through the casing from the chamber, a supplemental ring within the aforesaid ring forming passage-ways to behind the head and a suitable cover-plate to inclose the head as and for the purpose specified.

4. In a sound-producingdevice, the combination with the cylinder having passage-ways and the resonator leading therefrom, the exterior casing forming a chamber around the cylinder and a low-pressure pipe leading directly to the cylinder throughthe casing, of the piston having passage-ways corresponding to the passage-ways in the cylinder and located within the chamber in the casing and having an enlarged head provided with an a ring surrounding the 

